Roof Waste Factor Guide

When to Use 10%, 15%, or 20%

This guide explains exactly when to use 10%, 15%, or 20%+ waste factor on a shingle order. Simple gable roof: 10% waste. Hip roof: 12-15%. Cut-up roof with multiple valleys, dormers, skylights, or steep cricket flashings: 15-20%. Steep pitch (10/12+) or laminated/architectural shingles with random offset: add another 2-3%. Includes worked examples for three roof types and ties directly into our Waste Factor and Shingles calculators.